Fiber with improved complexation qualities and cation-exchange properties

ABSTRACT

The present invention concerns a process for treating a fiber or a fiber-based material such as a yarn, a woven, knitted or nonwoven textile material, paper, or leather, to improve its adsorption properties, wherein the following successive operations are carried out on said fiber or said material:
         a) applying a solid mixture of cyclodextrin(s) and/or cyclodextrin derivative(s) and/or inclusion complex(es) of cyclodextrin and/or cyclodextrin derivatives, at least one poly(carboxylic) acid and/or at least one poly(carboxylic) acid anhydride and optionally a catalyst;   b) heating to a temperature in the range 150° C. to 220° C.;   c) washing with water; and   d) drying.       

     The present invention also concerns fibers or fiber-based materials with improved cation exchange properties and improved hydrophilic characteristics.

The present invention relates to a process for treating a fiber or afiber-based material to improve its adsorption (complexing) properties.The present invention also relates to a fiber or fiber-based material,such as a textile, with improved adsorption properties.

BACKGROUND OF THE INVENTION

Improving the complexing properties of fibers allows different activecompounds such as fragrances, insecticides, bactericidal agents,antistatic agents, anti-bacterial agents or repellent agents to beadsorbed onto a fiber or fiber-based material. Because the adsorbedactive product subsequently diffuses into the surrounding atmosphere(release), the complexing phenomenon, which occurs in the fibers, endowsthe fiber or any material containing it with the different chemicalproperties of the adsorbed product for a set period that depends on therate of diffusion of the complexed product (release rate).

One known method for improving the adsorbent properties of a fiber isfixing (grafting) molecules of cyclodextrin(s) onto the fiber.

Cyclodextrins (α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin) havelong been known to be molecules possessing complexing properties, i.e.,molecules that are capable of reversibly trapping certain other smallmolecules of a hydrophobic nature, in particular aliphatic or aromaticmolecules, from their solutions, vapors or solid mixtures. The adsorbedmolecules are bonded to the cyclodextrin by the formation of inclusioncomplexes.

The release rate of the product complexed by cyclodextrins is small, sofibers functionalized by cyclodextrins are perfectly suited to producefiber-based materials, in particular textiles, which possess thechemical properties of the complexed product in a stable manner and forlong periods, and also to produce adsorbent materials. These adsorbentmaterials have a number of applications, in particular in waterpurification and contaminated gas purification.

Textile materials functionalized with cyclodextrins with adsorbedfragrances, antistatic agents, antimicrobial agents, insect repellents,bactericidal agents, or insecticides, have been respectively describedin the following documents: Japanese patent JP-A-06-116871, U.S. Pat.No. 5,376,287, JP-A-09 315920, JP-A-04-263617, JP-A-09-228144,JP-A-05-311509, U.S. Pat. No. 5,670,456 and JP-A-03-59178.

Textile materials functionalized by cyclodextrins and with hygroscopicand odor adsorption properties have been described in JP-A-06-322670,JP-A-02-127573, JP-A-03-14678, JP-A-08-199478, JP-A-02-251681 andJP-A-163372.

Textiles functionalized with cyclodextrins and used as adsorbents, inparticular as barriers to contaminants, have been described in U.S. Pat.No. 5,776,842.

These examples are not limiting. Potential applications for textilesfunctionalized with cyclodextrins have been cited by Denter andSchollmeyer in the document “Proceedings of the Eighth InternationalSymposium on Cyclodextrins”, Budapest, Hungary, 1996, J. Szejtli and L.Szente Eds, Kluwer Academic Publishers.

The principal technical difficulty in producing fibers and textilesfunctionalized by cyclodextrins or their inclusion complexes is to fixmolecules of cyclodextrin(s) or their inclusion complexes onto fibersand textile materials in a durable manner. A number of fixing methodshas been developed.

U.S. Pat. No. 4,357,468 describes a method for fixing cyclodextrin(s)using epichlorhydrin.

European patent EP-A-0 697 415, German patent DE-A-19520967 and DenterU., Schollmeyer E., J. Inclusion Phenom. Mol. Recognit. Chem. 25(1–3),197–202 (1996) describe a method for fixing cyclodextrins usingchlorinated heterocyclic compounds.

EP-A-0 488 294 and JP-A-03-59178 disclose a fixing method using reactiveaminosiloxanes and siloxanes.

U.S. Pat. No. 5,098,793 describes polymers obtained by reactingcyclodextrin with an activated dicarboxylic acid. Such polymers form afilm that adheres to the surface of a substrate that can be a cellulosesubstrate, for example. They do not contain any residual carboxylic acidfunctions because they come from dicarboxylic acid and since both of itscarboxylic acid functions have been reacted.

JP-A-06-322670 describes a fixing method using a resin based on anaminosilicone and/or polyurethane.

JP-A-02—127573 describes a fixing method using a polymer (Hercosett 57)obtained by cross-linking a polyamide with epichlorhydrin.

JP-A-09-228144 describes a fixing method by incorporating cyclodextrinsor their inclusion complexes into the chemical fiber spinning dope.

Finally, DE-A-4035378 describes a method for fixing cyclodextrin(s) orcyclodextrin derivative(s) using reactants carrying dimethylol ureagroups or derivatives of such groups that react both with a hydroxylgroup of the cyclodextrin and with a functional group of the fiber,bonding the cyclodextrin molecule to the fiber.

OBJECTS AND SUMMARY OF THE INVENTION

The present invention proposes a novel method for fixing cyclodextrin(s)or cyclodextrin derivative(s) that can fix molecules of cyclodextrin(s)or cyclodextrin derivative(s) in a durable manner to a fiber or a fiberbased material such as a textile, regardless of the nature of the fiberor fiber-based material under consideration.

The present invention concerns a process for treating a fiber or afiber-based material such as a yarn, a woven, knitted or nonwoventextile material, paper, leather, or a material based on wood fibers, toimprove its adsorption properties, wherein the following successiveoperations are carried out on said fiber or said material: applying asolid mixture of cyclodextrin(s) and/or cyclodextrin derivative(s)and/or their inclusion complexes, at least one poly(carboxylic) acidand/or at least one poly(carboxylic) acid anhydride and optionally acatalyst, heating to a temperature in the range 150° C. to 220° C.,washing with water and drying the product obtained.

The above inclusion complexes can, for example, be formed from an activeagent complexed by a molecule of cyclodextrin or a cyclodextrinderivative. A material treated with an inclusion complex has a betterguarantee of cyclodextrin complexing properties; the presence of acomplexed agent retains accessibility to the cavity of the cyclodextrin.

The process of the present invention is of particular advantage in thatit is applicable to any natural or artificial fiber and to any type offiber-based material such as a textile material, paper or leather, whichis capable of tolerating a heating step without undergoing eitherphysical or chemical degradation. In particular, the process of theinvention is applicable to fibers and to yarns composed of natural andartificial cellulose fibers, natural and artificial protein fibers,synthetic fibers such as polyesters, polyamides, acrylics, aramids,fluorofibers, or mineral fibers and to fiber-based materials andtextiles of the woven, knitted or nonwoven type and containing one ormore types of the above yarns and fibers.

The molecules of cyclodextrin(s) are fixed to the fiber or fiber-basedmaterial by two mechanisms that depend on the chemical nature of thefiber or the fiber-based material.

When treating fibers or materials composed of fibers comprising ahydroxyl and/or amine function, implementing the process of theinvention initially forms an anhydride of the poly(carboxylic) acid thatreacts with the fiber or fiber-based material by forming a covalentamide or ester type bond between the fiber or the fibers of the treatedmaterial and the poly(carboxylic) acid. Then, in the simplest case, asecond poly(carboxylic) acid anhydride is formed bonded to the fiber;this reacts with a molecule of cyclodextrin or cyclodextrin derivativeby creating an ester bond between the molecule of cyclodextrin orcyclodextrin derivative and that of the poly(carboxylic) acid. Possibleformation of an anhydride from a further carboxyl function of thepoly(carboxylic) acid bonded to the fiber then allows a reaction with afurther molecule of cyclodextrin or cyclodextrin derivative. In thatreaction, one or more molecules of cyclodextrin(s) or cyclodextrinderivative(s) is obtained bonded via an ester function to a molecule ofpoly(carboxylic) acid which is itself bonded to a fiber via a covalentbond.

Further, a second type of reaction may occur, either in parallel with orindependently of the reaction fixing the cyclodextrin or cyclodextrinderivative to the fiber via a covalent bond. Because of the presence ofpoly(carboxylic) acid, a copolymer of cyclodextrin and/or cyclodextrinderivative(s) and/or their inclusion complexes with poly(carboxylic)acid(s) is formed; this copolymerization produces copolymers that areeither linear, branched or cross-linked.

When the copolymer forms from a molecule of cyclodextrin fixed to thefiber via a covalent bond, it therefore has at least one covalent bondwith a fiber. When the copolymer forms from molecules ofpoly(carboxylic) acid and/or poly(carboxylic) acid anhydride andcyclodextrin and/or cyclodextrin derivative(s) not bonded to a fiber, ifit is cross-linked, i.e., forms a three-dimensional network minglingwith or coating the fiber or the fibers of a fiber-based material, itmay be mechanically fixed in a permanent manner to the fiber or materialunder consideration.

The basic mechanism using a molecule of poly(carboxylic) acid and amolecule of cyclodextrin or a cyclodextrin derivative is most probablysimilar to the mechanism for cross-linking cellulose withpoly(carboxylic) acids in the presence of a catalyst proposed by WelshC. M. in American Dyestuff Reporter 83(9), 19–26 (1994). Such atreatment, described in particular in U.S. Pat. No. 4,820,307 andcarried out on cotton cellulose, renders cotton textilescrease-resistant by cross-linking cotton fibers. However, that processis intended to modify the physical properties of a textile materialexclusively constituted by cellulose fibers, such as cotton, and not tomodify the adsorption properties of a fiber or a fiber-based material byfixing cyclodextrin(s) or cyclodextrin derivative(s) to the fiber or tothe structure of the fiber-based material, independently of the chemicalnature of that fiber or material, as in the present invention.

Further, certain synthetic fibers or materials based on such fibers donot possess functional groups that can react with the mechanism proposedabove. In this case, the cyclodextrin(s) and/or cyclodextrinderivative(s) and/or their inclusion complexes are fixed by forming across-linked copolymer obtained by exclusive reaction between themolecules of cyclodextrin(s) and/or cyclodextrin derivative(s) and atleast one poly(carboxylic) acid. The cross-linked copolymer formed coatsthe fiber or the fiber-based material in a permanent manner.

In the case of a fiber comprising an amine or hydroxyl function, such askeratinous or cellulose fibers, or a material comprising such fibers,the two fixing mechanisms coexist, namely fixing via a covalent bond tothe fiber and forming a sheath of cross-linked copolymer on the fiber.

The complexing properties of the cyclodextrins described above aresupplemented by those of the residual carboxylic acid functions whichhave not reacted by esterification, either with the fiber or with thecyclodextrin. These carboxylic acid functions endow the fibers not onlywith odor absorption properties but also with cation exchangeproperties. On the other hand, these carboxylic acid functions endow thefibers with better affinity for water (hydrophilic nature) and improvethe wettability of the treated material, in particular for materialsbased on slightly hydrophilic or hydrophobic fibers.

A further advantage of the process of the invention is that it is cheap,easy to carry out using equipment that is conventional in the textileindustry and that it does not necessitate the use of toxic reactants.

In a preferred implementation, the solid mixture is applied byimpregnating the fiber or fiber-based material with an aqueous solutionof cyclodextrin(s) and/or cyclodextrin derivative(s) and/or theirinclusion complexes, at least one poly(carboxylic) acid and/or at leastone poly(carboxylic) acid anhydride and optionally, a catalyst, thendrying the impregnated fiber or impregnated fiber-based material.

This impregnation and drying allows better incorporation of the solidreactive mixture into the fibers or causes it to penetrate it into thefibers, which subsequently facilitates both the reaction fixing thecyclodextrin to the fiber and obtaining a uniform deposit or coat of thecopolymer onto the fiber or the fibers of a fiber-based material.

In a preferred variation, the fiber or fiber-based material is dried ata temperature in the range 40° C. to 150° C., preferably 110° C. orsubstantially 110° C. before the heating operation proper, at atemperature in the range 150° C. to 220° C.

This prior drying step is particularly recommended in the case ofnatural fibers such as wool or cotton, to prevent their thermaldegradation.

This prior drying is advantageously carried out to obtain a solidmixture incorporated into the fiber or the fibers of the fiber-basedmaterial treated using the process of the invention, this drying beingthat following impregnation by an aqueous solution as described above.

Heating proper is intended to permanently fix molecules ofcyclodextrin(s) to the fiber or fiber-based material, by reactionbetween poly(carboxylic) acid and/or poly(carboxylic) acid anhydride andthe fiber or fiber-based material (chemical grafting by covalent bondingbetween the fiber and the molecule of cyclodextrin or cyclodextrinderivative, or the copolymer of cyclodextrin(s) and poly(carboxylic)acid(s) and/or by reaction between the poly(carboxylic) acid and thecyclodextrin and/or cyclodextrin derivative(s) to form a cross-linkedcopolymer (mechanical grafting by coating).

Preferably, the poly(carboxylic) acid and poly(carboxylic) acidanhydride used in the process of the invention are selected from thefollowing poly(carboxylic) acids and poly(carboxylic) acid anhydrides:saturated and unsaturated acyclic poly(carboxylic) acids, saturated andunsaturated cyclic poly(carboxylic) acids, aromatic poly(carboxylic)acids, hydroxypoly(carboxylic) acids, preferably selected from citricacid, poly(acrylic) acid, poly(methacrylic) acid,1,2,3,4-butanetetracarboxylic acid, maleic acid, citraconic acid,itaconic acid, 1,2,3-propane-tricarboxylic acid, aconitic acid,all-cis-1,2,3,4-cyclopentanetetracarboxylic acid, mellitic acid,oxydisuccinic acid, and thiodisuccinic acid.

Preferably, the mixture contains a catalyst selected from dihydrogenphosphates, hydrogen phosphates, phosphates, hypophosphites, alkalimetal phosphites, alkali metal salts of polyphosphoric acids,carbonates, bicarbonates, acetates, borates, alkali metal hydroxides,aliphatic amines and ammonia, preferably selected from sodium hydrogenphosphate, sodium dihydrogen phosphate and sodium hypophosphite.

Preferably, the cyclodextrin is selected from α-cyclodextrin,β-cyclodextrin and γ-cyclodextrin and the cyclodextrin derivatives areselected from hydroxypropyl, methyl or acetyl derivatives ofα-cyclodextrin, β-cyclodextrin and γ-cyclodextrin and inclusioncomplexes formed from said cyclodextrins and said cyclodextrinderivatives.

The present invention also concerns fibers or fiber-based materialspreferably obtained using the process described above, which areselected from fibers or fiber-based materials that comprise a hydroxylfunction and/or an amine function and which are bonded, via a covalentbond of an ester or amide type, to at least one molecule of cyclodextrinor to an inclusion complex of cyclodextrin or to a linear and/orbranched and/or cross-linked compound of cyclodextrin(s) and/orcyclodextrin derivative(s) and/or to an inclusion complex with at leastone poly(carboxylic) acid and wherein the structure comprises therepetition of a unit with general formula:

where 2<y<x−2; x≧3 and

n is 1 or more, and in which:

[Cell] represents the macromolecular chain of a natural or artificialcellulose fiber;

[Ker] represents the macromolecular chain of a natural or artificialprotein fiber;

represents the molecular chain of a poly(carboxylic) acid

where at least two carboxylic acid functions (COOH)_(y) have undergoneesterification and/or amidation and which comprises at least onecarboxylic acid function (COOH)_(x-y) that has not undergone anesterification or amidation reaction; and

[CD] represents the molecular structure of α-cyclodextrin,β-cyclodextrin γ-cyclodextrin, a derivative of cyclodextrin(s),preferably a hydroxypropyl, methyl or acetyl α-cyclodextrin,β-cyclodextrin or γ-cyclodextrin derivative, or an inclusion complex ofsaid cyclodextrins or said cyclodextrin derivatives.

The —O—CO— ester bond originates from the reaction between the hydroxylfunction of the cellulose fiber and the carboxylic function of thepoly(carboxylic) acid, while the amide bond —NH—CO— originates from thereaction between the amine function of the keratinous fiber and thecarboxylic function of the poly(carboxylic) acid. The poly(carboxylic)acid undergoes an esterification and/or amidation reaction of at leasttwo of its carboxylic acid functions and the cyclodextrin orcyclodextrin derivative undergoes esterification with thepoly(carboxylic) acid of at least one of its hydroxyl functions.

In the case of a fiber or a fiber-based material that does not reactwith poly(carboxylic) acids, the fiber or material obtained by theprocess of the invention is simply coated with a cross-linked copolymerof cyclodextrin(s) and poly(carboxylic) acid(s). In contrast, when thefiber or fiber-based material is based on cellulose and/or keratin orcomprises hydroxyl and/or amine functions, the molecules ofcyclodextrin(s) are fixed to the fiber or fiber-based material inaccordance with the two fixing modes described above, namely directfixation by covalent bonding to the fiber and coating of the fiber witha cross-linked copolymer.

The present invention accommodates these two types of fibers ormaterials, whether or not obtained by the process of the invention. Thepresent invention concerns fibers or fiber-based materials onto whichmolecules of cyclodextrin(s) and/or cyclodextrin derivative(s) are fixedonly by covalent bonding, fibers or fiber-based materials onto whichmolecules of cyclodextrin(s) and/or cyclodextrin derivative(s) are fixedby covalent bonding and by coating the fiber or fibers of the materialwith a cross-linked copolymer of cyclodextrin(s), and fibers orfiber-based materials onto which cyclodextrin is fixed solely by coatingwith a cross-linked copolymer, without limitation to the nature orstructure of said fibers or said fiber-based materials.

The materials can, for example, be knitted, woven or nonwoven textilescontaining cellulose and/or keratinous fibers and/or synthetic fibers.Such fibers or fiber-based materials comprising carboxylic acidfunctions possess excellent odor adsorption properties and, to a lesserextent, improved water absorption properties.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be better understood from the followingnon-limiting examples, which better illustrate the characteristics ofthe process of the invention and the fibers and fiber-based materials ofthe present invention.

Examples 1 to 11 illustrate the process of the present invention.Examples 12 and 13 illustrate the adsorbent properties of the materialsof the present invention and their possible use, in particular for theproduction of mosquito-proof clothing and mosquito nets.

EXAMPLE 1

5 grams (g) of a bleached cotton fabric with a weight of 100grams/meter² (g/m²) was impregnated, with the aid of a mangle, with anaqueous solution containing β-cyclodextrin (100 grams/liter (g/l)),citric acid (100 g/l) and sodium hydrogen phosphate [12-hydrate] (30g/l). The take-up was 100%. The fabric was dried for 3 minutes at 90°C., then treated for 5 minutes at 195° C., washed with copiousquantities of water and dried. The dry weight gain for the fabric was18%.

EXAMPLE 2

5 g of a bleached cotton fabric with a weight of 100 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining β-cyclodextrin (100 g/l), citric acid (100 g/l) and sodiumdihydrogen phosphate [hydrate] (30 g/l). The take-up was 100%. Thefabric was dried for 3 minutes at 90° C., then treated for 3 minutes at195° C., washed with copious quantities of water and dried. The dryweight gain for the fabric was 13%.

EXAMPLE 3

5 g of a bleached cotton fabric with a weight of 100 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining β-cyclodextrin (100 g/l), citric acid (100 g/l) and sodiumhypophosphite [hydrate] (30 g/l). The take-up was 100%. The fabric wasdried for 3 minutes at 90° C., then treated for 5 minutes at 195° C.,washed with copious quantities of water and dried. The dry weight gainfor the fabric was 12%.

EXAMPLE 4

5 g of a bleached cotton fabric with a weight of 100 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining β-cyclodextrin (100 g/l), 1,2,3,4-butanetetracarboxylic acid(100 g/l), and sodium dihydrogen phosphate [hydrate] (30 g/l). Thetake-up was 100%. The fabric was dried for 3 minutes at 90° C., thentreated for 5 minutes at 195° C., washed with copious quantities ofwater and dried. The dry weight gain for the fabric was 18%.

EXAMPLE 5

5 g of a bleached cotton fabric with a weight of 100 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining β-cyclodextrin (100 g/l), polyacrylic acid (100 g/l) andsodium hypophosphite [hydrate] (30 g/l). The take-up was 100%. Thefabric was dried for 3 minutes at 90° C., then treated for 5 minutes at195° C., washed with copious quantities of water and dried. The dryweight gain for the fabric was 19%.

EXAMPLE 6

5 g of a bleached cotton fabric with a weight of 100 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining γ-cyclodextrin (150 g/l), 1,2,3,4-butanetetracarboxylic acid(100 g/l) and sodium hypophosphite [hydrate] (30 g/l). The take-up was100%. The fabric was dried for 3 minutes at 90° C., then treated for 5minutes at 195° C., washed with copious quantities of water and dried.The dry weight gain for the fabric was 22%.

EXAMPLE 7

5 g of a bleached cotton fabric with a weight of 100 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining α-cyclodextrin (150 g/l), polyacrylic acid (100 g/l) andsodium hypophosphite [hydrate] (30 g/l). The take-up was 100%. Thefabric was dried for 3 minutes at 90° C., then treated for 5 minutes at195° C., washed with copious quantities of water and dried. The dryweight gain for the fabric was 22%.

EXAMPLE 8

5 g of a wool fabric with a weight of 120 g/m² was impregnated, with theaid of a mangle, with an aqueous solution containing β-cyclodextrin (150g/l), 1,2,3,4-butanetetracarboxylic acid (100 g/l), and sodiumhypophosphite [hydrate] (60 g/l). The take-up was 100%. The fabric wasdried for 3 minutes at 90° C., then treated for 5 minutes at 195° C.,washed with copious quantities of water and dried. The dry weight gainfor the fabric was 20%.

EXAMPLE 9

5 g of a hydrolyzed polyester fabric with a weight of 130 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining β-cyclodextrin (100 g/l), citric acid (100 g/l), and sodiumhydrogen phosphate [12-hydrate] (30 g/l). The take-up was 90%. Thefabric was dried for 3 minutes at 90° C., then treated for 5 minutes at190° C., washed with copious quantities of water and dried. The dryweight gain for the fabric was 19%.

EXAMPLE 10

5 g of a polyester fabric with a weight of 100 g/m² was impregnated,with the aid of a mangle, with an aqueous solution containingβ-cyclodextrin (100 g/l), citric acid (100 g/l), and sodium hydrogenphosphate [12-hydrate] (30 g/l). The take-up was 32%. The fabric wasdried for 3 minutes at 90° C., then treated for 5 minutes at 190° C.,washed with copious quantities of water and dried. The dry weight gainfor the fabric was 6%.

EXAMPLE 11

5 g of a polyacrylonitrile knitted fabric with a weight of 300 g/m² wasimpregnated, with the aid of a mangle, with an aqueous solutioncontaining β-cyclodextrin (100 g/l), citric acid (100 g/l) and sodiumhydrogen phosphate [12-hydrate] (30 g/l). The take-up was 90%. Thefabric was dried for 7 minutes at 90° C., then treated for 5 minutes at180° C., washed with copious quantities of water and dried. The dryweight gain for the fabric was 8%.

EXAMPLE 12

This example illustrates the adsorbent properties of fabricsfunctionalized with β-cyclodextrin using the process of the invention.Cyclodextrins are known to be capable of forming inclusion complexeswith phenolphthalein. Six samples of fabric functionalized withβ-cyclodextrin using the process of the invention, with a known mass andcontaining different quantities of β-cyclodextrin were placed insolutions of phenolphthalein with known concentrations. The variation inthe concentration of free phenolphthalein in each solution (A₀–A₉₆) wasmeasured by visible spectroscopy at 552.4 nanometers (nm) after 96hours. The changes in phenolphthalein concentration, expressed as thevariation in the optical density per gram of functionalized fabric, areshown in the table below:

Weight ratio of β-cyclodextrin 0 1.8 3.6 5.4 6.0 6.6 fixed to fabric (%)A₀–A₉₆/g of fabric 0.5 1.3 1.8 2.2 2.4 2.6

The ratio of cyclodextrin fixed to the textiles was measured using thedifference in dry weight gain between a fabric treated with acyclodextrin/poly(carboxylic) acid/catalyst mixture and a fabric treatedwith a poly(carboxylic) acid/catalyst mixture.

EXAMPLE 13

This example illustrates the use of textile materials of the inventionobtained by the process of the invention as textiles with mosquitorepellent properties. Diethyltoluamide (DEET) is a well known, widelyused synthetic mosquito repellent. Three samples of cotton fabric with aknown weight functionalized with cyclodextrins and obtained using theprocess of the invention using citric acid, sodium hydrogen phosphate[12-hydrate] and α-, β- and γ-cyclodextrins were placed in solutions ofDEET of known concentration. Adsorption of DEET onto the textilematerials was determined by measuring the change in absorbance of theinitial solution at 270 nm after 96 hours. The results are shown in thetable below:

Type of cyclodextrin Weight gain after used for functionalizationA₀–A₉₆/g Sample functionalization (%) of fabric 1 α-cyclodextrin 14 0.242 β-cyclodextrin 15 0.36 3 γ-cyclodextrin 15 0.34

The samples cited above were successfully tested as mosquito-repellenttextiles. The repellent properties of the fabrics were evaluated afterimpregnation with DEET and after the following treatments: aging byexposure to air for several weeks, irradiation using a UV lamp, raisingthe temperature, and washing with water. In some cases, the controlbased on cotton not functionalized with cyclodextrin, simply impregnatedwith DEET and which had undergone an identical treatment, had lost 100%of its effectiveness, while the fabrics of the present invention, whichhad been impregnated with DEET, retained 100% of their mosquitorepellent activity.

1. A process for treating a fiber consisting of: a. impregnating said fiber with an aqueous solution of a mixture to form an impregnated fiber, said mixture comprising
 1. one or more materials from the group consisting of cyclodextrins and cyclodextrin derivatives, and
 2. one or more materials selected from the group consisting of poly(carboxylic) acids and poly(carboxylic) acid anhydrides; b. drying said impregnated fiber at a temperature in the range of 40° C. to 150° C. to obtain a treated fiber; c. heating said treated fiber to a temperature between 150° C. and 220° C.; d. washing said treated fiber with water; and e. drying said treated fiber.
 2. A process according to claim 1, wherein the poly(carboxylic) acid and poly(carboxylic) acid anhydride are selected from the group consisting of saturated and unsaturated acyclic poly(carboxylic) acids, saturated and unsaturated cyclic poly(carboxylic) acids, aromatic poly(carboxylic) acids, hydroxy poly(carboxylic) acids, citric acid, poly(acrylic) acid, poly (methacrylic) acid, 1,2,3,4-butanetetracarboxylic acid, maleic acid, citraconic acid, itaconic acid, 1,2,3-propane-tricarboxylic acid, aconitic acid, all-cis-1,2,3,4-cyclopentanetetracarboxylic acid, mellitic acid, oxydisuccinic acid and thiodisuccinic acid.
 3. A process according to claim 1, wherein the catalyst is selected from the group consisting of dihydrogen phosphates, hydrogen phosphates, hypophosphites, alkali metal phosphates, alkali metal salts of polyphosphoric acids, carbonates, bicarbonates, acetates, borates, alkali metal hydroxides, aliphatic amines and ammonia.
 4. A process according to claim 1, wherein the cyclodextrin is selected from the group consisting of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, and wherein the cyclodextrin derivatives are selected from the group consisting of hydroxypropyl, methyl or acetyl derivatives of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.
 5. The process of claim 1, wherein said fiber has been formed into a material selected from the group consisting of yarn, woven textile material, knitted textile material, non-woven textile material, paper, leather and wood fiber-based material.
 6. The process of claim 1, wherein, in step (b), said impregnated fiber is dried at a temperature between 90° C. and 110° C.
 7. The process of claim 1, wherein said mixture further comprises a catalyst. 